The present invention relates to a transportable container for facilitating article transportation, and particularly, to a transportable container having an indicator for facilitating semiconductor wafer fabrication, and in particular to a pod to transfer wafers between process stations.
With the rapid advancement in the semiconductor package technology, designers are always tempted to scale the size of the package down. The industry of the package is striving to reduce the size and increase their speed simultaneously. An important consideration in making small, high speed and high-density devices is to provide packages that are capable of the spreading heat generated by the devices.
In general, any larger sizes particles can be very damaging to the semiconductor processing because of the feature size of the semiconductor devices is very small Undesired contamination particles substantially damage the product yield of the semiconductor devices. A SMIF (standard mechanical interface system) system is proposed to reduce particle on the semiconductor wafers during storage and transport of the wafers between the fabrication processes. The SMIF system provides a clean environment for articles. Further detail of disclosed prior art is described in the U.S. Pat. No. 4,532,970.
The system employs sealed pods for storing and transporting wafer cassettes. A sealed pod includes a top cover mating with a base. The wafers generally are seated within a wafer cassette that rests inside the pod. In order to transfer a wafer cassette from a source station to a destination in terms of SMF system. A pod is typically placed on a load port of the source station. After the destination is arrived, the cassette released from the load port, thereafter wafers are picked successively into the processing chamber by a robot.
Typically, the pod carry one or more cassette for transferring the wafers into the processing station. The cassette includes a structure for holding one or more wafer, which includes an open end from which the wafers may be inserted and extracted. A latch mechanism is provided within the base of the pod to control the latched on or off state of the pod door. The latch mechanism of the pod may include a cam kit, and a latch member. The latter has four keys and couples to the cam kit. The pod door is to ensure the four keys could be holding on the lock position when the cam is rotating into the end position.
However, the pod may be dropped to ground due to the door of the pod is not securely locked by the latch mechanic the cam does not complete the rotation and keep the cam staying at the end position, any violent motion may swing the four keys back to the unlock position. In this situation, it may cause the pod door to release from the pod base. The incident event occurred several times in the Fab.
What is needed is a transportable container having an indicator to indicate the pod door locked state.
The object of the present invention is to provide a container or pod having an indicator for SMIF.
The SMIF pod includes a base having a cassette that may receive one or more wafers in preparation for transferring the wafers. The base includes a plurality of first openings formed on the side surfaces for a latch mechanism. The base includes a window formed on a surface of the base for an operator to read the state of the container. A box top having second openings one to one corresponding to said first openings for the latch mechanism with latch member to penetrate through them while in the lock state. An indicator presents a first mark for indicating the locked state at the window or presents a second mark at the window for indicating the unlocked state.
The first mark and the second mark are coded on a rack, which is a member of the indicator. Another member of the indicator is a gear set coupled with the rack and the latch mechanism. The rack moving in a forward or backward direction is in response to the state of the latch mechanism.
Preferably, at least a first color and a second color marked on a terminal of the rack to indicate the state of the container or the SMIF pod. Alternatively, the mark may be presented by text or symbol in lieu of color.